Philippine E-Journals

Increasing Productivity of Yam (Dioscorea esculenta) through Improved Cultural Management Practices

Noralyn B. Legaspi | Beatriz S. Malab

Discipline: Agriculture

 

Abstract:

Yams (Dioscorea) are among the food sources in the country especially in times of food scarcity. D. esculenta, locally known as tugui, is one of two species, which are economically important in the Ilocos Region. Tugui thrives well in marginal areas and is considered as a cash crop by upland farmers. To date, no production technology has been developed for this crop; as such, productivity is relatively low at 2.6t ha-1- 3.3t ha-1 in farmers’ fields. Assessment of yam farmer’s current production practices shows the need to fine-tune some of its components. The most critical of them are fertilizer and seed management. Hence, field experiments were conducted to improve the existing cultural management practices for increased yam production. It was found that tugui can be successfully grown for three consecutive years without using fertilizer, as tugui farmers have been practicing ever since, with yields comparable with those applied with organic and inorganic fertilizers. Nevertheless, a declining trend in soil fertility of the unfertilized plots, implying the depletion of the soil’s natural fertility, which might cause the drastic decline in yield after three consecutive cropping seasons. However, applying two tons of organic fertilizer per hectare was found to sustain high yield and maintain the residual fertility of the soil after continuous cropping. With this, the capacity of the soil to produce high yield is sustained; therefore, shifting cultivation, a common practice among tugui growers, is minimized. In addition, the use of bigger setts (40-89 g) was found to significantly produce more vigorous plants and higher crop stand, resulting to an increase in yield by 138% as compared to the farmers’ practice of using small setts.