Thesis Abstract of AGS Students

Tippathorn Masjaroon (1995)

Wheat and barley have been introduced to Thai farmers for improving their income and substituting imports. However, farmers' adoption and the expansion of the two crops are constrained by various factors. The objective of this study is to investigate the key factors influencing the productivity and farmers' adoption of the two crops, including economic and non-economic aspects. The plot-level crop production data for the crop year 1992/93 were collected from major production areas in five provinces of the Upper Northern Thailand using multistage sampling. Descriptive statistics and production function analysis were employed to analyze the performance of wheat and barley crops.

Factors affecting farmers' decision in selecting wheat and barley are almost the same. The three outstanding factors include few alternatives to grow dry season crops in the areas, expectation of good returns, and farmers' perception of less labor required.

Farmers in the study area are found to use a number of tillage and sowing methods which differed from official recommendations. The key criteria that farmers considered in selecting practices include higher yields, lower cost, less labor, less physical work, ability to be sown in time and suitable to soil structure. Many farmers in irrigated environments also bought additional fertilizers for their crops. The average yield of wheat in 1992/93 was about 188 kg per rai for both rainfed and irrigated environments. Irrigated barley performed higher yield than rainfed barley with about 159-162 kg per rai compared to 122 kg per rai. The yield levels for each production practice were markedly different and great variation in yield was notable in all systems. The damage caused by rats was reported as the most serious constraint of both wheat and barley. In addition, disease infection in barley was also a serious factor causing yield reduction. An increase in fertilizer use and the change in agronomic practices were reported as the key factors in achieving good yields.

An economic analysis showed that the unit production cost of wheat and barley were higher than the price of produce. The lowest unit production cost was observed in rainfed wheat having a cost of about 8 baht per kg. However, excluding non- cash costs, the unit cost was reduced to 2 baht per kg with input subsidy or 5 baht per kg without subsidized inputs. Irrigated wheat had a unit cost of about 12 baht per kg. With subsidized inputs, farmers spent cash 3.4 baht per kg. The unit cost was about 7 baht per kg when farmers have to purchase all of input used. Rainfed barley required the highest unit production cost of about 15.5 baht per kg or 8.6 baht per kg only for variable cash cost. Barley production in other environments incurred similar costs. With respect to the returns, the wheat farmers obtained positive returns over ariable costs (under input subsidy) of about 381 baht per rai in rainfed areas and 264 baht per rai in irrigated areas. In barley cultivation, farmers got positive returns over variable cash cost only in irrigated lowland and rainfed conditions, accounting of about 286 and 349 baht per rai, respectively. Barley required higher production cost and performed lower yield than wheat but was compensated by a higher selling price resulting in little difference in the returns between the wheat and barley. Taking into account family labor and cost of subsidized inputs, farmes got negative net profit from wheat and barley production in every system. However, for good farmers who can achieve high yields, there is still potential to be exploited in the two enterprises.

Using production function analysis, this study explored the relationship between yield per rai and determining input variables such as; farm size, seed rate, nitrogen, phosphorous, and labor To investigate effects of crop management, dummy variables were also assigned in the models. The best functional forms were found in polynomial using generalized least square (GLS) and ordinary least square (OLS) methods of estimation. The regression results revealed that expanding of farm size in lowland production systems had a negative effect on yields of both wheat and barley. Current high seed rate tended to cause reduction in yield for lowland wheat but it provided positive response to upland barley yield. Nitrogen fertilizer was found to have positive effect on yields in all production systems. However, yields of wheat showed more response to nitrogen nutrient than barley. To improve productivity of wheat and barley crops, an increasing rate of nitrogen fertilizers are recommended for irrigated areas where farmers practiced appropriate crop managements. Only barley yield showed significant response to phosphorous nutrients. In rainfed conditions, the yields showed marked response to labor use but increasing number of labor should be considered only in rainfed wheat production where the marginal product of labor input was higher than the wage rate. Furthermore, the dummy variable of crop management suggested that the extension services should pay more attention in correcting farmers technical errors. This may help to improve productivity of wheat and barley.

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