The Latest Control Measures for Stem Blight in Pitaya

During pitaya cultivation, farmers often encounter stem blight and various other diseases, which seriously affect yield and growing returns and restrict the development of the pitaya industry. So how should pitaya stem blight be controlled? Let's take a look together.

I. Symptoms

When the disease occurs, irregular grayish-white lesions form on the ribs of the plant, covered with many small black dots. The lesions are sunken and gradually dry up, eventually forming notches and holes. They mostly occur on the middle and lower stem segments.

II. Disease Pattern

The stem blight pathogen overwinters with diseased stems on the soil surface. When the spring temperature rises above 3 degrees, it begins to multiply, and at 15 degrees it releases spores that infect the plant's fleshy stems. The optimum temperature for disease development is 20-30 degrees. Conidia spread through rain splash and air to cause secondary infections, mainly harming the fleshy stems of pitaya. The disease generally begins in late March, when it has just started to cause damage, the diseased plant rate is still low, and the disease develops slowly. After April, as temperatures rise, the disease worsens, and by May to July it reaches its peak period. This is just before flowering, and because of the high temperatures and the arrival of the rainy season, the best conditions for pathogen infection are created, so the disease spreads extremely quickly in the field. In addition, areas with low-lying terrain and heavy clay soil have a higher incidence of disease than areas with higher sandy loam soil, and excessive application of nitrogen fertilizer also aggravates the disease.

III. Integrated Control Measures

1. Agricultural control

Select and breed disease-free seedlings. If seeds are to be selected, be sure not to transfer or introduce seeds from diseased areas, and at the same time choose varieties with strong disease resistance. This is the most economical and effective measure for controlling pitaya diseases. After harvest, promptly remove diseased and residual branches and field weeds to keep the field clean and reduce the pathogen base. During the growing period, strengthen fertilizer and water management. Do not use flood irrigation, as it may suffocate the roots and kill them. Drip irrigation and ridge cultivation are best. Apply more organic fertilizer and phosphorus and potassium fertilizer to improve disease resistance.

2. Chemical control

You can use Bordeaux mixture, prochloraz, prochloraz manganese salt, thiophanate-methyl, mancozeb, carbendazim and other agents for propagation, spraying once every 7-10 days, for 2-3 consecutive sprays.

The above is an introduction to the control measures for pitaya stem blight. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.