Wheat in the rice-based farming system of the Punjab: implications for research and extension

Abstract

The planting of wheat after rice is a major cropping pattern in the Punjab, occupying 0.5 million ha. in the Districts of Sheikhupura and Gujranwala alone. In this irrigated area, however, wheat yields remain low and research is urgently needed to find ways of increasing productivity in this important region. As part of NARC's outreach program, a diagnostic survey of wheat was conducted in the Districts of Sheikhupura and Gujranwala in the 1983/84 crop cycle in order to delineate major sources of variation in the area, identify major factors limiting productivity and plan an on farm experimentation/extension program. An informal survey by a team of agricultural economists and wheat agronomists was conducted in February, 1984. This was followed by a survey of wheat production practices and yields at harvest time in 152 fields. Production practices were recorded in a short interview with farmers and yields measured by harvesting and threshing a sample of the crop. Wheat after Basmati rice was the dominant crop rotation in the area, followed by wheat after IR-6 rice. Wheat was produced on two major soil types (based on soil survey classifications) imperfectly drained days and well drained loams and clay loams. Seedbed preparation for wheat was often very poor reflecting the difficulties of preparing land after rice, especially in heavy soils. After Basmati rice these problems were greater because of the limited time available for land preparation and the greater rice residue problem. As a result of poor land preparation, stand establishment was often poor and weed growth was encouraged. These factors combined to produce low wheat yields especially in heavy soils and after Basmati rice. The majority of farmers used banned wheat varieties, especially Yecora (58%). Only 16 percent used approved varieties released in the last 5 years. An inadequate seed distribution system and poor extension of information on newer varieties were the major factors constraining use of newer varieties. Since Yecora is susceptible to both leaf and stripe rust, there is a real danger of a serious rust epidemic. Late planting of wheat in December and into January occurs in over half of the wheat fields. This is particularly true when wheat follows Basmati rice. The later harvest of Basmati and the need to obtain a suitable moisture condition for land preparation for wheat often leads to late planting. The majority of farmers now use 80kg/ha of nitrogen and 57kg/ha of phosphorus (i.e. 1 bag/acre each of urea and diammonium phosphate). In better prepared fields and fields with better access to irrigation water, fertilizer rates are somewhat higher leading to higher yields. The most important element explaining variation in yields was nitrogen. Most farmers appear to apply adequate phosphorus. Phalaris minor is a serious weed problem in a quarter of all fields leading to an average reduction in yield of about 25 percent in these fields. Broadleaf weeds are also a problem in some fields but with less yield damage. Farmers control Phalaris to some extent through crop rotation, especially by planting berseem. The survey showed that very few fields of wheat after berseem in the previous year were infested with Phalaris. Herbicides are used by only a handful of farmers. The high cost of herbicides in relation to returns, equivalent to 500kg of wheat/ha or 27 percent of average yields at the recommended dose, is an important obstacle to wider herbicide use. 9. Irrigation practices vary substantially depending on access to canal and tubewell water. Many farmers who obtain water from publicly owned tubewells faced serious water shortages due to mechanical breakdowns in these tubewells. The effect on yields in 1983-84 was not large due to timely rains. Harvesting, threshing and transport costs account for over 25 percent of the total value of wheat harvested. While the official price of wheat is R 1600/ton (64 R for 40 kg) the net price that should be used in calculating the profitability of an innovation is about R l,100/ton (R42 per 40 kg) when harvesting and post-harvest costs are deducted. Average yields from the 152 samples were 1.8t/ha but quite variable. Twenty percent of fields yielded under 1.0 t/ha and only 7 percent yielded over 3.0 t/ha. The characteristics of the high yielding fields were: (a) lighter soils (b) wheat after maize or other non-rice crops, (c) sown with a newer variety (e.g. Punjab 81), (d) better land preparation, (e) earlier planting (f) 50 percent more nitrogen and (g) more irrigations. Conversely, low yielding fields had usually been planted continuously to wheat in the rabi cyde, usually followed Basmati and were seriously infested by Phalaris weed. Multiple regression analysis of yields confirmed most of these factors as significantly affecting yields. Overall, the regression analysis explained half of the variation in wheat yields. There is an urgent need to stratify the farmers in the area into more homogeneous groups (i.e. recommendation domains) for the purpose of formulation of recommendations. Major delineations should be based on soil type and access to irrigation water. Research and extension should direct efforts to evaluating and promoting newer varieties of wheat, finding economic means for controlling weeds and seeking solutions to the problem of poor stand establishment. A series of experiments/verifications to meet these objectives in both the should and longer run are proposed. This research should be conducted in farmers fields within the 61elineated recommendation domains. There is also a need for rice and wheat researchers to integrate efforts to develop appropriate cropping systems that increase total productivity of the cropping system.