Effects of soil management, pollination, and nitrogen fertilizers on Williams' pear trees

Abstract

The effect of soil management, pollination, and level and timing of nitrogen fertilizer on mature spurpruned Williams' pear trees under irrigated conditions was studied. The dominant response was due to soil management; straw mulch was better than cultivation, and cultivation was equal to clover sward in yield, but was inferior in vigour. Cross pollination improved yield, and tended to depress growth for both straw mulch and clover sward plots, but had little or no effect in cultivation. The various nitrogen treatments produced no important differences except that unfertilized trees declined in growth though not in yield, and the growth decline was slower than expected. After the fertilizer trials were concluded, the clover sward treatment was lifted in production to almost equal straw mulch. This improvement was probably due to the introduction of less severe pruning and the use of weedicides along the tree line.