FACTORS RESPONSIBLE FOR LOW YIELD OF WHEAT (Triticum eastivum L) IN 2017/2018 DRY SEASON IN JIGAWA STATE, NIGERIA
Wheat is one of the most important staple food crops of the World (Bilgi, 2006) and it occupies first position in terms of production and utilization and contributes more calories and proteins to the World’s human diet than any other cereal (Bilgi, 2006). It was therefore against this background that many farmers participated actively in the production of this robust crop within the state. However, it was unfortunately along the line that the program was faced with so many challenges which invariably resulted in low yield compared to 2016/2017 cropping season. Some of the factors that militated against the successful production of this versatile crop include but not limited to the following:
- CLIMATIC FACTORS: These entail the following:
- Abrupt changes in temperature
Wheat being a temperate crop is highly sensitive to sudden variation in temperature, as such; its cultivation in tropical and sub-tropical regions of the world with Nigeria inclusive is faced with many obstacles. The most critical being the sudden and drastic fluctuation in temperature during the growing season which has a direct bearing on crop growth and yield, respectively. In fact, crop species generally differ in their response to temperature and each crop has an optimum temperature in which it exhibits maximum growth and yield and below or above this optimum limit, yield declines drastically. However, in a worst case scenario zero yields are obtainable. For example, the mean minimum temperature on 8th February, 2018, was 17oc and the following day it suddenly rises to 40oc. Similarly, on 6th March, 2018, the minimum temperature was 19oc but abruptly changed to 41oc the next day. This shows how unstable the weather conditions were during the growing season. This is one of the implications of climate change (global worming) which has negative consequences on crop production. This is particularly so in wheat which exhibits high sensitivity to such abrupt weather changes than any other cereal available for cultivation. This is the simple reason why wheat cultivation is basically confined to dry winter season when there is a cool and dry weather condition that favours its growth and yield. To this end, the low yield of wheat recorded in this cropping season could be directly or indirectly associated with sudden fluctuations in the mean daily temperature during the growing season.
- High temperature during the productive phases
It was reported that the optimum range of temperature for good tillering in wheat is 16 – 20oc and contrarily, the temperature range that coincided with tillering stage in this very cropping season was 18.5 – 32oc which was far above the optimum range of 16 – 20oc.This necessitated the wheat plants to abruptly switch from tillering to heading pre-maturely, leading to low productivity. This might be the case, hence, it has been reported that at mean daily temperature higher than 20oc in the early tillering phase, tillering ceases and heading is accelerated resulting in few numbers of spikes per unit area, as a result of which yield declines. The report that yields per unit area is more of a function of number of plants involved than the potential of individual plant justifies this statement. In the same vein, it was also reported that the best temperature range for booting, heading, flowering and grain filling and maturity in wheat is 20 – 25oc. However, at temperature higher than 25oc in the grain development phase, the plants dry up pre-maturely, leading to the production of malformed grains, which subsequently becomes manifested in low yield. In contrast, the temperature range recorded in the months of February and March, 2018, which unfortunately coincided with grain formation stage were 23 – 39oc and 24 – 45oc, respectively, which were actually far above the optimum range of 20 – 25oc. In view of this, the low yield of wheat recorded in this dry season was attributable to high temperatures experienced within the growing season as vividly highlighted above.
- Unexpected rainfall:
The low yield of wheat observed in this dry season could as well be ascribed to unexpected rains that were received on 23rd February, 2018, which amount to 13.21mm. This basically affected the wheat plants in a negative direction. To crown it all, where the precipitation period coincided with that of flowering, the affected wheat plants produced no grains at all being that the flowers were washed away by the rain water prior to pollination, which led to zero yield in most of the affected areas. The zero harvest experienced by Mal. Wada Ibrahim Gumel out of three acres in Gezozi village, kazaure zone, buttresses this point. In the same vein, where the rainfall period matched with the time when the wheat field was irrigated, the affected wheat plants dry up pre-maturely due to excess soil moisture and high humidity (58%), with zero yields being the case in worst hit areas. This was exactly what happened in Jekarade irrigation scheme, Kazaure, where nothing was harvested out of two acres due to this natural calamity.
HUMAN FACTORS: These are subdivided into:
- Use of poor quality seeds:
High quality seed is a key to crop production as seed of low quality usually result in poor harvest. However, some farmers are in the habit of planting grains that were obtained from local markets not seed which normally lead to low yield. And once this occurs, farming becomes physically strenuous, time consuming and economically unrewarding in nature.
- Non adoption of modern farming techniques:
It is rather unfortunate that some farmers still stick themselves tenaciously to their local methods of farming with poor harvest being the end result. It should be noted that each crop has a recommended agronomic practices that guide its production and for the inherent yield potential of that particular crop to be fully expressed, such agronomic practices must be carried out as recommended. Likewise, the productive capacity per unit area may not be fully exploited which subsequently becomes reflected in low yield which implies low economic returns.
- Late planting:
Another possible reason that is responsible for low productivity per unit area which appears to be a common practice among the farming communities is late planting of crops. It should be noted that crop production is time bound and if what is suppose to be done today is left till next week, the one week delay may affect the genetic potential of the crop which more often than not becomes manifested in low yield. However, with all the vagaries related to climate change as highlighted above, those farmers who were opportune to plant around middle or late October to early November were able to get reasonable yields. This can be exemplified by Mal. Makki Ahmed Ibrahim Yalleman, Hadejia, who planted on 13th October, 2017 and was able to get 2.67 t ha -1. More so, farmers who planted early enough were able to escape the adverse effect of 23rd February rains, hence, the wheat plants were harvested prior to that period. Ironically, most of the farmers who planted late November to early December, obtained an average yield of less than one tone per hectare. To be precise, A. Saidu Muhd and Mal. Nasur Muhd, all in Dabi town recorded 0.4 and 0.65 t ha –1, respectively. The same situations were observed in Lafiya and Gagiya areas, all in Guri local government. This apparently justifies the positive effect of early planting on crop productivity as opposed to late planting which appears to be a common phenomenon among the farmers.
Causes of late planting
Some of the remote causes of late planting are vividly enumerated below:
- Untimely release of fund and procurement of farm inputs
In relation to government sponsored program on agriculture, late planting is some times being associated with delay either in the disbursement of fund or in inputs procurement and distribution all of which are practically and humanly avoidable where there is much commitment.
- Inconsistent farming calendar
Another reason that brings about late planting is the extension of rain fed rice production to October or even November in most of the fadama areas due to unplanned cropping season. This usually consumes part of the time meant for dry season farming. This appears to be the case with Jigawa Research Institute, Kazaure, being that the Institute has no cultivable Fadama land within its jurisdiction. Consequently, the Institute has to wait for other farmers to harvest the late planted rain fed rice before they can get chance to plant which also culminated into late planting.
- High Level of poverty among farmers
Majority of the small scale farmers are living from hand to mouth, as such do not have the financial capacity to purchase all the necessary farm inputs at the right time which invariably paves way to late planting. This implies that agric loans and subsidies are indispensible, if the dream of ensuring sustainable food security and poverty eradication is to be actualized.
SUGGESTIONS FOR IMPROVEMENT
Based on the aforementioned, the following suggestions were given which if properly put into practice, will go a long way in reducing the problems to a manageable level
- Though, climatic variables are beyond human control, however, the risk could be drastically minimized if recommended agronomic practices are fully adopted, such as manipulation of the planting time to take the advantage of the cool weather condition that prevails during the months of November through January, planting early maturing crop varieties, timely farm operations and using cultivars that can withstand adverse weather conditions without slumping in production
- As crop production is time oriented in nature, early planting should be encouraged among the farming communities in order to enhance high productivity per unit area and better economic returns. This will in turn be reflected in the reduction if not total elimination of the man’s ancient enemies (hunger and poverty) in our dear nation.
- Timely release of fund and procurement of farm inputs by the authority concern are of paramount value and should be adopted for profitable and sustainable agriculture. For example, all the inputs needed for dry season farming should be ready at least by September or October, being that the planting activities are usually kick-start in November. While that of rain fed farming should be made available latest by March or April, since, in the northern parts of the country, rainy season usually start late May to early June. This may assist greatly in eliminating the habit of late planting among the farming communities.
- Government intervention in terms of agric loans and subsidies should be intensified so as to uplift the socio-economic status of the small scale farmers. This will definitely motivate them to be more productive. However, for such incentives to have a positive impact on the target individuals, real farmers should be the focus but not farmers on paper as some times being the case
Dr. Abubakar K. Karaye can be reached at
Jigawa Research Institute, Kazaure
Jigawa State, Nigeria