Pink Root (Pyrenochaeta terrestris) affects onions, garlic, leeks and shallots. The disease is active to a depth of up to 45 cm in the soil. When air temperatures reach 24- 28 degrees Pink Root disease activity accelerates and is often seen on onion roots. Fusarium regularly works in conjunction with the Pink Root infestation.
Perlka gave good control of Pink Root in a hybrid onion crop when applied 14 days before sowing, reducing the instance of root and plant infestation by almost 60% compared to the control. The standard control application was Ammonium Nitrate. The soil type was a medium loam with pH of 7.3. Perlka is 19.8% Nitrogen and 50% Calcium Oxide.
Perlka distributor in the United Kingdom, Paul Corfield has extensive experience with Perlka use on onions. This includes using rates of Perlka at 400 kilo /hectare on onions. The grower considered the results to be a success with improved strength of the foliage resulting in a high quality skin finish and firmer, more dense bulbs. At these same rates, there also appeared to be good control of Fusarium.
The non-leaching benefits of Perlka resulted in the grower requiring less nitrogen. This benefit, coupled with the crop having more available Calcium makes Perlka an ideal fertiliser for onions.
What is Perlka
Perlka is manufactured from natural raw materials, coal, limestone and atmospheric nitrogen. When combined with electricity they form a well proven nitrogen fertiliser.
Perlka is composed of
- 19.8% Nitrogen : less unwanted nitrates without a drop off quality.
Perlka is a long term nitrogen source that has to go through several transformation processes in the soil to become fully available to the plants. The nitrogen supply corresponds to the natural growth demands of young plants. Ammonium nitrogen remains in the soil for a long time. Loss of nitrogen through leaching is minimal making Perlka the ideal fertiliser for irrigated crops as well as crops grown in areas of high rainfall. Throughout onion production areas of New Zealand this is often the case, especially in the 4 month period after sowing.
- 50% Calicum oxide: This is readily available to the plant via soil moisture.
Perlka has a lime content of 50% (CaO). This is highly reactive and long term use of the product has shown that the pH of the soil will remain constant without further additions of lime.
Worldwide scientific reportage has identified that physiological disorders in vegetables are on the increase. These include tip burn in lettuce, black heart in celery and blossom end rot in tomatoes. Regular applications of Perlka can help to reduce these problems.
Over 50 years of Perlka use studies filed in Europe have shown very positive soil fertility effects from periodic applications of Perlka. These have been due to major increases in soil microbial enzymes, which are well regarded scientifically to be an indicator of soil fertility.