Table of Contents

1. Introduction
2. Nutritional effects on fruit yield
3. Quantitive nutrient requirements of kiwifruit
   1. Timing of fertiliser additions
4. Diagnosis of nutritional disorders
   1. Soil testing
   2. Plant analysis
   3. Visual symptoms

   Please note that pages in the following sections 5 through 8 are at least 80K in size including thumbnail images

5. Disorders producing symptoms mainly on the older leaves
   1. Deficiencies

      1. Potassium deficiency

      2. Magnesium deficiency

      3. Nitrogen deficiency

      4. Zinc deficiency

      5. Phosphorus deficiency

      6. Chlorine (Chloride) deficiency

   2. Toxicities

      7. Boron toxicity

      8. Salinity

      9. Manganese toxicity

      10. Nitrogen excess

      11. Phosphorus toxicity

6. Disorders producing symptoms mainly on recently matured leaves
   1. Deficiencies

      12. Manganese deficiency

      13. Calcium deficiency

7. Disorders producing symptoms mainly on the younger leaves
   1. Deficiencies

      14. Iron deficiency

      15. Sulphur deficiency

      16. Boron deficiency

      17. Copper deficiency

      18. Molybdenum deficiency

   2. Toxicities

      19. Zinc toxicity

8. Symptoms associated with non-nutritional disorders

   20. Drought stress

   21. Bacterial leaf spot

   22. Low temperature

   1. Herbicides

      23. Glyphosate (Roundup®)

      24. Terbuthylazine+Terbumeton (‘Caragard’)

      25. Diuron + Methabenzthiazuron (‘Amatin’)

      26. Simazine

   2. Hormone herbicides

      27. 2, 4-D

      28. 2, 4, 5-T

9. Glossary of terms
10. List of references
11. Appendices

 Introduction

The kiwifruit Actinidia deliciosa (A. Chv) C.F. Liang et A.R. Ferguson var deliciosa is a deciduous fruiting vine indigenous to provinces along the Yangtze River in South-Western China^15,17. The emergence of kiwifruit as a major horticultural crop is a very recent phenomenon; outside of China where there is substantial production from wild stands of kiwifruit.

Kiwifruit was first introduced into New Zealand at the beginning of the century, but it was not until the 1930s that commercial scale planting’s were made³⁶. Small areas continued to be planted over the next 30 years culminating in a dramatic increase over the late 1970s and 1980s.

From the few hundred hectares in the early 1970s, the area planted 1995/96 exceeded 10 000 ha. Planting’s in New Zealand are almost exclusively of the one cultivar, "Hayward" - a survey of kiwifruit orchards in the Bay of Plenty in 1979 showed that "Hayward" occupied 98 per cent of the total area in kiwifruit¹⁷. From 1997, plantings of new varieties are now occuring.

Apart from brief descriptions of several nutritional disorders produced on hydroponically grown kiwifruit plants⁵⁰, little attention has so far been given to the diagnosis of nutritional disorders in kiwifruit. In New Zealand, this was largely because the kiwifruit industry was initially confined to the deep volcanic ash soils of the Bay of Plenty where few obvious nutritional problems were encountered.

However, plantings now include other regions: North Auckland, Auckland, Poverty Bay, Hawkes Bay, Taranaki, Horowhenua, and Nelson.

With this expansion onto soils with characteristics differing from those of the Bay of Plenty has come an increasing number of problems attributable directly to mineral nutrition.

The purpose of this booklet is to bring together information about the mineral requirements of kiwifruit and , in particular, to describe fully visual symptoms to nutrient deficiencies and toxicities. In addition, descriptions are given of some important leaf symptoms due to non-nutritional causes so they can be distinguished from nutritional problems.