JPS6147802B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a method for preventing fruit drop of apples and pears before harvest, which is characterized by using α-(24-dichlorophenoxy)propionic acid and its salts and esters as an active ingredient at 10 to 30 ppm during the fruit drop period. Regarding. Conventionally, the current problem in the cultivation of apples and pears in Japan is that new varieties of apples and pears have been cultivated and new management measures have been required. Specifically, new varieties such as the apple ``Tsugaru'' and the pear ``Shinsui'', ``Kosui'', and ``Hosui'' suffer from severe fruit drop as the ripening period progresses, and this results in stable production due to fruit drop before harvest. Prevention has become an essential condition. In addition to these varieties, these preventive measures have the greatest impact on yield and quality, including the conventional apple varieties ``Kugyoku'' and ``Deliciyas,'' and pears ``Nijisseiki'' and ``Chojuro.'' These factors have led to strong demand for countermeasures. In the past, a number of drugs have been proposed for these purposes, and some of them, such as sodium α-naphthalene acetate (hereinafter abbreviated as NAA) and 245-TP, have been put into practical use. Since these drugs have caused problems such as toxicity, there has recently been a desire for a drug to replace them. The present inventors have compared and investigated the effects of pre-harvest fruit drop prevention on apples and pears using a number of compounds that have already been confirmed to have plant hormone effects.
It has been recognized that it is extremely difficult to achieve a preventive effect using a desirable drug, as it depends on complex factors such as plant physiology and cultivation conditions. However, in such a situation, α
- (24-Dichlorophenoxy)propionic acid and its alkali salts such as sodium salts and potassium salts, amine salts, ammonium salts, and its lower alkyl esters such as ethyl ester have been found to have extremely good preventive effects. However, the present invention was achieved. That is, the preferred concentration is 10~
30ppm is to be sufficiently sprayed on the fruit, the leaves of the fruit clump, and the entire surface of the tree at the beginning of signs of fruit drop in apple and pear varieties that are particularly prone to fruit drop as mentioned above. Additionally, if the harvest period is delayed for more than a month, it is an effective method to perform additional spraying in the same manner one more time. 3. Remove fruit drop using the above method.
It is possible to keep it below ~5% and make a significant 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 for agrochemical formulation to form wettable powders, emulsions, powders, and floatables. It can be used in any dosage form. The active ingredients of the present invention include, for example, clay, talc,
Solid carriers such as white carbon, diatomaceous material ±, bentonite, and higher alkoxysulfonates,
By mixing and grinding with an ionic or nonionic emulsifier or dispersant such as polyoxyethylene sorbitan, alkyl phenoxy polyethoxy ethanol, lignin sulfonate, and if necessary, a wetting agent, a protective colloid agent, etc. A hydrating powder can be obtained. 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 concentrate can also be present as a water-in-oil concentrate and as an oil-in-water concentrate with a thick mayonnaise-like consistency. The active substance in the present invention can also be used in combination with other acaricides, insecticides, fungicides, plant growth regulators, fertilizers, etc. Examples and test examples are shown below. Example 1 20 parts of α-(2,4-dichlorophenoxy)propionic acid, 70 parts of clay, 5 parts of white carbon,
2 parts of higher alcohol sulfate ester and 3 parts of lignin sulfonate are uniformly mixed and ground to make a wettable powder.
Got 100 copies. Example 2 20 parts of α-(2,4-dichlorophenoxy)propionic acid ethyl ester, 73 parts of xylol, 3 parts of polyoxyethylene alkyl ether, 2 parts of polyoxyethylene alkylallyl ester, and 2 parts of calcium dodecylbenzenesulfonate were uniformly mixed and stirred to obtain 100 parts of an emulsion. Test example 1 1 Test method Test tree: Apple “Tsugaru” Spraying period: August 18th Treatment method: Treatment by tree, 3 repetitions per section. Spraying was done using a small sprayer to cover the chemical solution sufficiently. 2 Test results

【table】

[Table] Test example 2 1 Test method Test tree: Pear "Kosui" 11th grade Spraying date: August 30th Treatment method: Treatment by tree, 3 repetitions per section. Spraying was done using a small sprayer to cover the chemical solution sufficiently. 2 Test results

[Table] According to the above test, in the invention plot, 2.4-
It showed a more desirable effect than D, and the same or better effect in preventing fruit drop than NAA. It was also confirmed that the fruit quality was good in terms of sugar content, hardness, acid content, coloring, etc.

Claims (1)

[Claims] 1. A method for preventing apples and pears from falling before harvest, characterized by containing α-(24-dichlorophenoxy)propionic acid and its salts and esters as an active ingredient.