AGRICULTURE TRIBUNE Monday, November 5, 2001, Chandigarh, India
 

Low-pressure drip irrigation
G.S. Dhillon
L
ow-head drip irrigation came to be introduced in Kenya around 1995 by the Christian Mission Aid and KARI (Kenyan Agricultural Research Institute) and since then it has gained popularity, particularly in kitchen garden irrigation. Water being scarce in Kenya, the womenfolk managing the kitchen gardens had to either bring water from a distance or after operating hand pumps.

Bacterial stalk rot disease in maize
Ashwani K. Basandrai, Akhilesh Singh and V. Kalia
M
aize is a staple food of rural poor, especially in hilly areas of North India. In Himachal Pradesh, maize is grown in an area of about 3.2 lakh hectares with a total production of 6.71 thousands tonnes. The average yield, about 21.0 q/ha, is much above the national average. With the introduction of high-yielding hybrid varieties from the private and public sector, the yield is likely to increase in the near future. Surplus produce, thus, may be used as poultry feed, fodder and for industrial purposes.

Intensive research is need of the hour
K.S. Chawla
T
he continuously growing food and nutritional security requirements due to a progressively increasing population, shifts in dietary pattern, economic growth and trends of the world market under the WTO can be expected to significantly change the supply-demand food profiles in the country. Therefore, intensive research efforts will have to be made to understand and manage the bio-physical potentials of different agro-eco-regions (an even zones within a region).

Farm operations for November

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Low-pressure drip irrigation
G.S. Dhillon

Low-head drip irrigation came to be introduced in Kenya around 1995 by the Christian Mission Aid and KARI (Kenyan Agricultural Research Institute) and since then it has gained popularity, particularly in kitchen garden irrigation.

Water being scarce in Kenya, the womenfolk managing the kitchen gardens had to either bring water from a distance or after operating hand pumps. The low-head irrigation in the form of "bucket drip" (see figure) to deliver water for the crops grown, which provided a most effective mode and involved far less effort and that too at minimum cost, came to be welcomed.

Advantages offered by this mode of irrigation are it is water saving, labour saving, low cost and simple to install and maintain.

The drip-line with a 50-litre bucket and 30m drip-line is the most commonly adopted mode and it can accommodate large growing beds. In Kenya, this set-up has been found profitable by hundreds of poor families and the marginal farmers as it enables them not only to produce enough vegetables for their families but also surplus for sale.

Caution: This mode may involve some problems which can be easily overcome by a cautious farmer. The drawbacks are breakage of filter plugs on account of plastic becoming brittle after some use and exposure to the elements; low-flexibility in term of emitter spacing and length of lateral; the drip-line may get punctured by sharp objects if not properly handled, clogging of some of emitters, non-uniformity of emitter discharge along the laterals, especially where the land being irrigated is not well levelled, and leakage at the bucket connection.

The conventional drip system comprises over-sophisticated and over-engineered control elements compared to the low cost low-head mode under discussion. The low-head drip system operates under pressure of 0.5 to 2 m of water-head compared to 10 to 15 m water-head needed for conventional drip irrigation.

A used oil-drum instead of a bucket, if adopted, will provide a large volume of water which will require refilling after longer intervals. The drims can be supported by "blocks". Perforated flexible plastic piping convey water to the plants.

The technology has been found to be a promising one which can respond to shortages of water and food in arid and semiarid areas. This mode, in addition to being used for kitchen gardens by housewives, can also be adopted by the farmers for plots growing paddy seedlings and other crops requiring transplanting.

Low-head drip irrigation technology promises an improved food yield and hence security and increased incomes at the household level, ultimately culminating in a healthy national economy.

Low pressure (0.05 to 0.2 bar) operating pressure has many advantages and it enables substantial enlargement of the cross section of the labyrinth flow passage of each emission unit, which simultaneously avoids clogging.

The drip rate can be reduced down to 1.2 litres per hour per metre despite the large flow passage. The lower drip rate means larger lateral lines and diameter reduction of distribution and main lines and also of the other control elements.

It enables use of lateral produced from a very thin but strong plastic film made from a specially tailored polymer, which helps reduce cost of laterals. Optimal growing conditions can be achieved because the very low drip rate which enables round-the-clock irrigation at peak season.

Emitter spacing may very from 30 to 40 cm and the wall thickness between 0.25 to 0.5 mm and the tape diameter of 16 m. The set-up marketed by KARI costs $ 19 per bucket-kit.

The bucket is mounted on a stand, which holds it one metre above the ground level. The drip lines are supplied in the lengths of 15 m, and for best results, they are laid on level ground. If the drip lines go up a small slope, the bucket or drum should be placed on the highest side.

The lines are laid with emitters facing up, to reduce the problem of sediment settling on the emitters. In the case of the drum system, the drum system, the drum is connected to a manifold with fine openings each to cover a bed. The manifold includes a PVC pipe, bends, a gate valve, tees, and ‘glue’ for fittings.

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Bacterial stalk rot disease in maize
Ashwani K. Basandrai, Akhilesh Singh and V. Kalia

Maize is a staple food of rural poor, especially in hilly areas of North India. In Himachal Pradesh, maize is grown in an area of about 3.2 lakh hectares with a total production of 6.71 thousands tonnes. The average yield, about 21.0 q/ha, is much above the national average. With the introduction of high-yielding hybrid varieties from the private and public sector, the yield is likely to increase in the near future. Surplus produce, thus, may be used as poultry feed, fodder and for industrial purposes. Most of the commercial hybrids are highly susceptible to bacterial stalk rot. Since the environmental conditions i.e. temperature and humidity during the kharif crop season are very conducive for the disease development in the low and foothills, terai and valley areas of North India, popularisation and extensive cultivation of such high-yielding but susceptible hybrids may result in severe epiphytotics, as was experienced in the Balah valley in Mandi district in 1968 where epidemics of the disease causing 80 to 90 per cent crop losses occurred due to cultivation of hybrid variety Ganga 3. On an average this disease causes 5 to 30 per cent losses in different areas.

The disease was reported for the first time in the USA in 1922. It occurs in South Rhodesia, Israel, Greece, Nepal, South Africa, the USA and possibly Mexico. In India, it was reported in Pusa (Bihar) in 1930. The disease is quite destructive in high rainfall areas eg. terai regions of Uttar Pradesh and Bihar. The epidemic of the disease results in reduction in grain yield and fodder.

Symptoms: The disease initiates at the lower nodes and affects the stalks up and down to a very limited extent. Rot causes soft dark decay of rind and generally interior of the stalk is rotted. The infected stalks become soft and turn into dry mass of shredded, easily disjointed fibres and the plant topples down. Upper leaves show symptoms of wilting, internodes becomes discoloured, leaf sheaths and leaves covering that also become discoloured and yellow. The rind losses natural dark green colour and becomes pale straw coloured. It appears as if it is boiled in water. Ear shoots and cobs occasionally get infected directly, but these droop down and hang limply on infected plants. Ultimately the stalk breaks and the plant collapses.

The disease is caused by a bacterium, Erwinia chrysanthemi pvzeae. It is a pectolytic bacterium causing parenchymatous necrosis and vascular wilt. The organism is soil borne and lives sapropgytically on diseased plant debris and in the rhizosphere of non-host plants. The bacterium can survive in field soil containing host debris for about a year. It causes infection at the base of the stem in the subsequent crop. Soil moisture and temperature influence survival of the bacterium. A temperature of 30- to 35°C and frequent rains during flowering favour infection and disease development. The pathogen enters through wound injury, stomata or hydathodes, weak spots resulting from extension of endogenous roots and injured brace roots. Insect injury, accumulation of water around the stem and relatively high temperature also favour infection.

Disease management
Cultural practices:
Waterlogging and dense planting should be avoided.

High nitrogen without P2O2 and K enhances disease incidence whereas, high dose of P and K reduces it, so balanced dose of NPK should be applied.

Chemical control: The pathogen is highly sensitive to chlorine. Drenching the basal stalk region at the knee-high stage with bleaching powder (CaOCl2, H2O) containing 33 per cent chlorine is highly effective. The studies conducted at RRS, Dhaulakuan, indicated that three applications of bleaching powder 10 per cent @ 16.5 kg/ha at the time of sowing, earthing up and tasselling were highly effective in decreasing disease incidence and increasing yield.

Host Resistance: Cultivation of resistant varieties are practically feasible and most effective method to manage this disease. Local open pollinated varieties and composite var. Navin are highly tolerant to the disease, whereas commonly grown hybrids like KH 101, KH 517, KH 581, PCSL 4640, Ganga 5 Sartaj etc. have been found to be susceptible whereas, hybrid var. PCSL 3438 has field tolerance.
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Intensive research is need of the hour
K.S. Chawla

The continuously growing food and nutritional security requirements due to a progressively increasing population, shifts in dietary pattern, economic growth and trends of the world market under the WTO can be expected to significantly change the supply-demand food profiles in the country. Therefore, intensive research efforts will have to be made to understand and manage the bio-physical potentials of different agro-eco-regions (an even zones within a region). These observations have been made by Dr M.S. Bajwa, a renowned soil scientist, in his document, "Strategies for agricultural research and development — a plan for Punjab".

Gaps between the achievable production potentials and the present levels of productivity will have to be narrowed. Such trends of increasing agricultural production will have to be maintained by efficiently managing the constraints of shrinking natural resources, declining per capita land holdings, emerging biotic and abiotic stressed, international competition, uncertain weather conditions, tight IPR regime and environmental stresses.

According to Dr Bajwa, about 45,000 species of plants are found in India (12 per cent of global). Of these 15,000 species are of higher plants and 30,000 of economic value. Among the higher plants, 5,000 species constitute the useful botanical wealth under the following use based groups — food 1200 species, fodder 1200 species, fuel timber 1000, medicine 1500, fibre 150, shlter 150 species and oils 100. The Shivalik region in Punjab, which once supported dense vegetation of diverse plant species, is now presenting a highly degraded look. With the passage of time, depletion of agro biodiversity has occurred due to changes in the system of agriculture, abandoning of traditional crops and varieties in favour of new ones, over-grazing, excessive harvesting and deforestation.

Dr Bajwa emphasises that biodiversity is the basic requirement for successful plant breeding. A wide range of genetic source materials provided by the land races has made it possible to make advances in modern plant breeding. This very success, however, has started depleting the source of genetic biodiversity on which will depend the future progress.

So far, the crop improvement research has mainly been aiming at the development of high yielding input-responsive varieties of crops. Since population is progressively growing and there and geographical and agro-climatic limitations for further expansion for area under high yielding varieties of crops, the crop improvement research has to be a continuous process not only for maintaining high yields but also for achieving future breakthrough in obtaining high quality produce. This calls for strengthening of research to develop hybrids, bioengineered crop varieties and superplant types (super rice and super wheat) capable of giving high product and products of a globally competitive quality even under emerging biotic and abiotic constraints.

According to Dr Bajwa, in Punjab, the hybrids produced so far have given adequate yield advantage in maize, pearl millet, cotton, mustard, sunflower, pigeonpea and some vegetable crops. In the case of rice, although a number of hybrids have been developed in different states with public and private sector efforts yet sufficient advantage in terms of yield gains has not been achieved.

Swiss-based scientists are developing genetically engineered rice (golden rice that is fortified with vitamin A and iron) containing genes (obtained from daffodils) capable of producing high levels of B-carotene and related compounds which are converted in human body into much needed vitam A. Such types of bio-engineering researches can be of great human and economic significance. Similar types of studies need to be carried out for future breakthrough.

Research needs to be strengthened towards the improvement of export-oriented crops like basmati rice, durum wheat, soyabean, flowers, vegetables, fruits and others.

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Farm operations for November

Wheat:

— Sowing of long-duration varieties of wheat like PBW-343, WH-542, PDW-274, PDW-233, PBW-34 and PBW-154 should be completed up to the second and third weeks of November. After this period, prefer to sow PBW-373 and PBW-138. Under rainfed conditions grow PBW-396, PBW-299 and PBW-175. Do not grow durum wheat in light soils as well as in soil deficit in manganese.

— Drill 55 kg of DAP and 35 kg of urea or 55 kg of urea and 155 kg of superphosphate per acre at the time of sowing. Urea can also be applied before ‘rauni’ irrigation. Muriate of potash @ 20 kg per acre may be applied in soils testing low in available potash. But in the districts of Gurdaspur, Hoshiarpur and Ropar 40 kg muriate of potash need to be applied. Urea dose may be reduced by one-fourth if it followed legume fodder.

— To rainfed wheat 70 kg of urea, 100 kg of single superphosphate and 16 kg of muriate of potash per acre may be drilled at the time of sowing in medium to high moisture storage capacity soil (sandy loam and finer soils). In loamy sand soil (low moisture storage capacity), the fertiliser dose may be reduced to half.

— In recently reclaimed salt-affected soils, the urea dose may be increased by 25 per cent.

— In case zinc sulphate has not been applied to the previous crop of rice or maize, a dose of 25 kg of zinc sulphate per acre may be applied at the time of sowing.

— For control of loose smut of wheat, treat the seed of all wheat varieties except that of PDW-274, PDW-233, PBW-34 and TL-1210 with Vitavax @ 2g/kg or Bavistin/Agrozim/Derosal/JK Stein/Sten 50 @ 2.5 g/kg seed and for the control of root rot, foot rot, seedling blight, black tip and black spot of glumes, treat the seed with Captan/Thiram @ 3 g/kg seed. Captan and Thiram treatment should not be done earlier than one month of sowing as it affects seed germination. These fungicides can be used to control leaf/flag smut.

— For control of mamni, put the seed in ordinary water and agitate vigorously. The galls will float on the surface. These may be removed with sieve and burnt. Dry the seed and use for sowing.

Yellow and brown rust: Grow rust resistant varieties like PBW-343, WH-542 and PBW-34 under normal sown conditions and PBW-373 under late sown conditions.

— Termite is a serious pest of wheat, particularly in rainfed area. Before sowing, seed must be treated with 160 ml of chlorpyriphos (Dursban/Ruban/Durmet 20 EC) or 280 ml Endosulfan (Thiodan 35 EC). Dilute anyone of the above mentioned insecticide in one litre of water and spray on one acre seed (40 kg) spread on the ground in a thin later.

Pulses:

— In lentil use varieties like LL-699, LL-56 or LL-147 and complete sowing by mid November. For higher yields, inoculate the seed with Rhizobium culture. Apply 10 kg of urea and 50 kg of superphosphate per acre at the time of sowing. If the Rhizobium culture has not been used, then apply 100 kg of superphosphate per acre at sowing.

— In gram, use PBG-1 or C-235 in the submontane districts whereas GL-769 or GPF-2 varieties be used in other districts. The sowing must be completed by the first week of November as further delayed in sowing results reduction in yield. Prefer the PDG-3 and PDG-4 variety under rainfed conditions.

— Treat the seed with Bavistin and Thiram (1:1) or Hexacap/Captain/Captaf @ 3 g/kg seed for the control of blight. Grow resistant varieties C-235 and PBG-1.

— Treat the seed of pea with Bavistin @ 1 g/kg seed for control of wilt.

Rapeseed and mustard:

— Under November sowing, transplanting of gobhi, sarson is more profitable than direct sowing. Use 60-day-old seedlings of gobhi sarson (PGSH-51) transplant 30 to 40 days old seedlings. Raya RLM-619 can also be sown during this month but African sarson PC 5 gave more seed yield than RLM 619.

— To early sown raya, apply 45 kg of urea per acre with first irrigation. In rainfed conditions, apply 33 kg of urea and 50 kg of single superphosphate per acre by drilling at the time of sowing.

— Sometime hairy caterpillar become a serious pest on toria. For its control, spray 500 ml of Thiodan 35 EC or 200 ml of Nuvan 85 SL in 125 litres of water.

Sugarcane:

— Irrigate the crop at monthly interval. Start crushing/harvesting early maturing varieties like CoJ-86, CoJ-64, CoJ-83 and CoJ-85.

Celery:

— Start transplanting celery crop from November 15 at a spacing of 45 x 25 cm. Use 65 to 70 days’ old seedlings. At the time of transplanting apply 90 kg of urea and 100 kg of superphosphate per acre.

Fodder production:

— Take the first cutting of berseem.

— Conserve the surplus maize fodder as silage at milk dough stage.

— Take the last cutting of napier bajra in early November because further delay will cause mortality of stumps. — Progressive Farming, PAU

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