How to treat pear tree top rot? Silicon-calcium-magnesium fertilizer has good control effect

Pear top rot, also known as pear stem rot and pear iron-head disease, generally occurs on European pear varieties, so it is also called European pear top rot. The causative factor of pear top rot is currently unclear and is generally considered a physiological disease. In order to seek effective control methods, we conducted a control experiment using silicon-calcium-magnesium fertilizer and achieved good results. The experimental results are summarized as follows.

(1) Experiment and methods:

(1) Experimental materials. The experiment was set up in a pear orchard in Xishanbeitou Village, Dayao Town, Muping District, Yantai, Shandong, with the variety Bartlett pear, tree age 11 years, soil type sandy loam, flat terrain, irrigation available, overall orchard management level good, tree vigor moderate, and uniformity relatively good.

The experimental fertilizer selected was silicon-calcium-magnesium fertilizer produced by the chemical fertilizer plant of Shandong Zibo Jinfeng Chemical Co., Ltd., with main component contents of silicon 35%, calcium 20%, and magnesium 10%. This fertilizer is rich in highly effective silicon, calcium, and magnesium secondary elements, and can be used to improve soil, adjust soil pH, improve fruit quality and disease resistance of fruit trees, and control various physiological diseases.

(2) Experimental methods: A total of 4 treatments were set up in the experiment, namely (1) conventional fertilization + 1 kg per tree; (2) conventional fertilization + 2 kg per tree; (3) conventional fertilization + 3 kg per tree; (4) the conventional fertilization area as the control. Each treatment had 20 trees, repeated 2 times. Before pear trees bloomed, the fertilizer was broadcast once under the tree canopy, followed by deep hoeing and one thorough watering.

Before fruit harvest, 5 trees were randomly selected from different treatments, and according to the five directions of the tree canopy - east, west, south, north, and center - 50 fruits were taken from each tree, and the number of diseased fruits and diseased fruit rate were counted separately, and the control effect was compared with the control.

(2) Experimental results:

(1) The results showed that silicon-calcium-magnesium fertilizer had a relatively good control effect on pear top rot, but the control effects of different application rates differed to some extent. In 2003, the control effects of the three treatments of applying 1 kg, 2 kg, and 3 kg of silicon-calcium-magnesium fertilizer per tree were 63%, 81%, and 83% respectively, while the diseased fruit rate of the control was as high as 63%; in 2004, the control effects of applying 1 kg, 2 kg, and 3 kg per tree were 79%, 96%, and 97% respectively, while the diseased fruit rate of the control was as high as 66%, and the control effect was very obvious.

(2) It can also be seen from the experiment that silicon-calcium-magnesium fertilizer can significantly improve the appearance quality of the fruit, making the fruit surface smooth and fine, reducing the occurrence of Bartlett pear fruit russeting, and increasing its commercial value; at the same time, the new shoots of trees treated with silicon-calcium-magnesium fertilizer grew noticeably longer, single fruit weight increased, and yield increased significantly.

(3) As a medium-element and micro-element fertilizer, silicon-calcium-magnesium fertilizer can promote the growth and development of fruit tree roots, activate soil, improve the physical and chemical properties of soil, promote the balanced absorption of various nutrient elements by fruit trees, and thereby correct and prevent nutrient deficiency symptoms in fruit trees. In production, according to tree age and size, applying 2-3 kg per tree is appropriate.