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Fruits
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Printable Version |
- Plant Nutrient Needs of Mango
A three year PPI/PPIC financed series of field trials with mango in Guangdong province, China was conducted by Zhou Xiuchong, Liu Guojian, Yao Jianwei, Ai Shaoying and Mo Wenxiong of the Guangdong Academy of Agricultural Sciences', Soil and Fertilizer Institute.
Plant nutrient removal studies showed that an average fruit yield of 18.7 t/ha absorbed 22.4 kg/ha N, 9.0 of P2O5 , 44.7 of K2O, 3.2 of Ca, 3.0 of Mg and 2.3 kg/ha of S. At the indicated yield, this amount of each of the respective plant nutrients can be expected to be removed from the field when the fruit is harvested. This gives a nutrient absorption ratio of 100 : 40 : 200 : 14 : 13 : 10 for the 6 plant nutrients.
Recommended economic plant nutrient application rates (kg/ha) for the soil and climatic conditions of Guangdong were found to be 342 of N, 107 of P2O5, 274 of K2O, 34 of Mg, and 34 of S when the plant population was 2.92 x 4 m (855 trees/ha).
Dramatic response to K by mango in Guangdong
- Balanced Fertilization Improves Yield and Quality of Litchi in Guangdong Province
Litchi is one of the major fruits and economic crops, whose production is very important to rural economy and farmers’ income in Guangdong province. In recent years, Guangdong Academy of Agricultural Sciences has done a series of research on quality litchi with balanced fertilization technology to achieve high yield and to serve farmers with technical guidance in large areas.
The experiments were conducted in Shenzhen, Dongguan and Huadu district of Guangdong province. The results were given in Table 1. Fertilization with 709g of N, 284g of P2O5，887g of K20，71g of Mg，142g of S per tree obtained a yield of 18,297 kg/ha (62.7kg/tree). One single fruit weighed 19.8g. With this fertilizer application, the net income reached 150,528 yuan/ha, surpassed that of farmers’ practice by 89,172 yuan/ha. All the results showed that balanced fertilization with N, P, K, Mg and S application on quality litchi of Guiwei and Luomichi increased single fruit weight by 1.0g, yield by 6,734 kg/ha or 58.2%, solid content by 1.2%, soluble sugar by 1.1%, and Vc by 1.1mg/100g, respectively. Besides, organic acid was reduced by 0.01% and fertilizers cost by 31.3%. Balanced fertilization increased net income by 61,356 yuan/ha or 68.8% compared with the farmers’ practice.
Table 1 Economic benefit as affected by different treatments
Note: Price of fertilizers: urea 1300 yuan/t, single superphosphate 400 yuan/t, imported DAP 2200 yuan/t, KCl 1400 yuan/t, MgCl2 1300 yuan/t, import 15-15-15 compound fertilizer 2300 yuan/t, SPM 1300yuan/t, sulfur 2500 yuan/t.
Litchi price: 9 yuan/kg
- Potassium Boosts Banana Production in Hainan Province
In the past two years, the important role potassium (K) plays in Hainan's banana production was demonstrated. Without application of KCl, banana have poor yields and low quality or even barren shoots under extreme cases (see attached photo of K vs. -K treatment on banana growth in Hainan). Either case can be observed in banana plantations in Hainan province.
Photo 1. Banana plants with applied K (left) vs. -K (right) in Hainan.
The Minus K treatment resulted in barren shoots in this experimental field.
It is well-known that banana is a K-loving crop. To produce 45-60 tonnes (t) of good quality banana, generally an application of over 1000 kg of K2O/ha is needed to meet the demand of banana. The extremely high requirement of banana for K in Hainan island can be attributed to the island's unique soil and climatic conditions. The prevailing soil types on Hainan are sandy in texture. In some areas the soil looks like pure sand inherited from parent material of alluvial deposits of the sea, providing the soil with very poor fertility. Besides, high rainfall accelerates leaching of plant nutrients, particularly N and K. These factors make the soils extremely deficient in soil-K. As a result, application of KCl on banana usually increases fruit yield by greater than 20%, and in some cases, even over 100%.
There are about 35,000 ha of banana planted on Hainan island. If every farmer applies KCl to banana at the rate used in the experiment, it will consume 35,000 to 50,000 t more K2O per year for banana alone. This will not only increase banana yields by over 20 % but also improve considerably their quality and farmers' income.
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