JPS6345362B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preventing fruit drop of apples and pears before harvest, which contains 2-methyl-4-chlorophenoxybutyric acid or its salts or esters as an active ingredient. Nowadays, the current problem in the cultivation of apples and pears in Japan is that new varieties (for example, the apple ``Tsugaru'',
Pears "Nijisseiki", "Kosui", "Shinsui", "Hosui", etc.)
In cultivation, pre-harvest fruit drop becomes more severe as the ripening period progresses, and this is further exacerbated by climate and weather conditions. For this reason, ensuring stable production and shipping preparation through drug treatment is an essential condition and is considered to be an extremely important issue. For this purpose, a number of drugs have been proposed in the past, including, for example, sodium α-naphthalene acetate (hereinafter abbreviated as NAA) and 2,4,5-TP.
Although some drugs have been put into practical use, recently there has been a desire for the emergence of drugs to replace them. As a result of our search for a practical fruit drop preventive agent, the present inventors found that 2-methyl-4-chlorophenoxybutyric acid and its alkali metal salts such as sodium salt and potassium salt, lower alkyl esters such as its ethyl ester, and its amine salts. It has been found that lower alkylamine salts such as triethanolamine salts and the like can be used as fruit drop preventive agents. These compounds, such as 2-methyl-4-chlorophenoxybutyric acid ethyl ester, are known as herbicides for upland and paddy fields, and it is extremely clear that they can be used safely and effectively as a fruit drop prevention agent for apples and pears. This should be called a surprising new fact. That is, the preferred concentration is 20 to 40 ppm of the active ingredient to be applied to apples and pears at the beginning of signs of fruit drop, preferably from 10 days before harvest to just before harvest.
In addition, it is necessary to sufficiently spray the entire surface of the tree. Furthermore, if the harvest period is delayed for more than one month, it is more effective to perform additional spraying in the same manner one more time. By using the above method, it is possible to suppress fruit drop to less than 5 to 10%, and there is no harm to quality or trees, making a huge contribution to profits. In carrying out the present invention, the above-mentioned active ingredients are mixed or combined with one or more conventional additives or auxiliaries according to the usual methods of agrochemical formulation, and are prepared in the form of wettable powders, emulsions, powders, etc. It can be formulated and used. The active ingredients of the present invention include, for example, clay, talc,
Solid carriers such as white carbon, diatomaceous earth, bentonite, and higher alkoxysulfonates,
A wettable powder can be obtained by mixing and grinding with an ionic or nonionic emulsifier or dispersant such as polyoxyethylene sorbitan, alkyl phenoxy polyethoxy ethanol, or lignin sulfonate. Furthermore, an emulsion can also be obtained by dissolving the compound according to the present invention in a suitable solvent and then adding an appropriate amount of the above-mentioned surfactant. The active substance in the present invention can also be used in combination with other acaricides, insecticides, fungicides, plant growth regulators, fertilizers, etc. Hereinafter, the production of the preparation used in the method of the present invention will be illustrated as a reference example, and then the method of the present invention will be explained with reference to test examples. Reference example 20 parts of 2-methyl-4-chlorophenoxybutyric acid,
70 parts of clay, 5 parts of white carbon, 2 parts of higher alcohol sulfate and 3 parts of lignin sulfonate were uniformly mixed and ground to obtain 100 parts of a wettable powder. Reference Example 20 parts of 2-methyl-4-chlorophenoxybutyric acid ethyl ester, 73 parts of xylene, 3 parts of polyoxyethylene alkyl ether, 2 parts of polyoxyethylene alkyl allyl ester and 2 parts of calcium dodecylbenzenesulfonate were uniformly mixed and stirred, 100 parts of emulsion were obtained. Test example: 15-year-old apple with good growth and uniformity (variety Tsugaru)
Two mature trees (~) were selected and four branches were selected to serve as the test plot (Table). Test example: 10 year old pear tree (20th century) with good growth and uniformity 2
Trees (~) were selected, and 4 branches were selected as test plots (Table). Five days before harvest, each test plot was uniformly sprayed with each active ingredient. In addition, on the 20th day after treatment, the number of fallen fruits in each test plot was investigated, and the results shown in the following table were obtained.

【table】

【table】

[Table] According to the above test, in the invention plot, the control
It was found to have a desirable fruit drop prevention effect that is equivalent to or better than NAA. It was also confirmed that the fruit was of good quality in terms of sugar content, hardness, coloring, etc.

Claims (1)

[Claims] 1 Pre-harvest fruit drop of apples and pears using a composition containing 2-methyl-4-chlorophenoxybutyric acid, its alkali metal salts, its lower alkyl amine salts, or its lower alkyl esters as an active ingredient. How to prevent it.